 /*******************************************************************************
  * Copyright (c) 2005, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.ui.internal.cheatsheets;

 import org.eclipse.core.commands.ParameterType;
 import org.eclipse.core.commands.ParameterizedCommand;
 import org.eclipse.core.commands.common.CommandException;
 import org.eclipse.core.commands.common.NotDefinedException;
 import org.eclipse.core.expressions.IEvaluationContext;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.commands.ICommandService;
 import org.eclipse.ui.handlers.IHandlerService;
 import org.eclipse.ui.internal.cheatsheets.data.CheatSheetCommand;
 import org.eclipse.ui.internal.cheatsheets.views.CheatSheetManager;

 /**
  * Execute a command defined in a cheatsheet
  */

 public class CommandRunner {
     
     private ICommandService getCommandService() {
         IWorkbench wb = PlatformUI.getWorkbench();
         if (wb != null) {
             Object serviceObject = wb.getAdapter(ICommandService.class);
             if (serviceObject != null) {
                 ICommandService service = (ICommandService)serviceObject;
                 return service;
             }
         }
         return null;
     }
     
     private IHandlerService getHandlerService() {
         IWorkbench wb = PlatformUI.getWorkbench();
         if (wb != null) {
             Object serviceObject = wb.getAdapter(IHandlerService.class);
             if (serviceObject != null) {
                 IHandlerService service = (IHandlerService)serviceObject;
                 return service;
             }
         }
         return null;
     }
     
     /**
      * Attempt to execute a command
      * @param command a CheatSheetCommand created by the parser
      * @param csm
      * @return OK_STATUS if the command completes withour error, otherwise
      * an error status
      */
     public IStatus executeCommand(CheatSheetCommand command, CheatSheetManager csm) {
         ICommandService commandService = getCommandService();
         IHandlerService handlerService = getHandlerService();
         if (commandService == null || handlerService == null) {
             return new Status
             (IStatus.ERROR,
             ICheatSheetResource.CHEAT_SHEET_PLUGIN_ID, 0,
             Messages.ERROR_COMMAND_SERVICE_UNAVAILABLE, null);
         }

         ParameterizedCommand selectedCommand;
         Object result;
         String rawSerialization = command.getSerialization();
         try {
             String substitutedSerialization = csm.performVariableSubstitution(rawSerialization);
             selectedCommand = commandService.deserialize(substitutedSerialization);
             IEvaluationContext state = handlerService.getCurrentState();
             result = selectedCommand.executeWithChecks(null, state);
             
             String returnsAttribute = command.getReturns();
             if ((returnsAttribute != null) && (result != null)) {
                 ParameterType returnType = selectedCommand.getCommand().getReturnType();
                 if ((returnType != null && (returnType.getValueConverter() != null))) {
                     String resultString = returnType.getValueConverter().convertToString(result);
                     csm.setDataQualified(returnsAttribute, resultString);
                 }
                 else {
                     if (result instanceof String ) {
                         csm.setDataQualified(returnsAttribute, (String )result);
                     }
                 }
             }
             
         } catch (NotDefinedException e) {
             String message = NLS.bind(Messages.ERROR_COMMAND_ID_NOT_FOUND, (new Object [] {rawSerialization}));
             return new Status(IStatus.ERROR, ICheatSheetResource.CHEAT_SHEET_PLUGIN_ID, IStatus.OK, message, e);
         } catch (CommandException e) {
             return commandFailureStatus(e);
         } catch (Exception e) {
             return commandFailureStatus(e);
         }
         
         return Status.OK_STATUS;
     }
     
     private IStatus commandFailureStatus(Exception exception) {
         return new Status
         (IStatus.ERROR,
         ICheatSheetResource.CHEAT_SHEET_PLUGIN_ID, 0,
         Messages.ERROR_COMMAND_ERROR_STATUS, exception);
     }

 }

